The field of the present invention pertains to the art of adjustable linear locking assemblies. More particularly, the present invention relates to adjustable linear locking assemblies that can be conveniently adjusted to different fixed positions.
The prior art reflects a long-standing endeavor to create mounting devices which simplify the process of positioning and mounting an item and which expand the latitude concerning where and how a mounted, hanging, or otherwise secured item can be repositioned. For example, as has been repeatedly noted in a multitude of patents granted over the last century (including those discussed below, the disclosures of which are incorporated herein by reference), hanging an item such as a picture or painting in a precise desired position on a wall can prove frustrating and time consuming. For one thing, it is often difficult to discern exactly where an item will look best until it has already been hung in the vicinity of the desired position, and then, from the proper perspective, viewed hanging. Even when an exact desired position is known in advance, imprecision or errors in measurement usually occur (to different degrees depending on the hanging hardware used) and commonly prevent that location from actually being obtained on the first try. Finally, even when an exact position is known in advance, and it is satisfactorily obtained through luck or work, the addition or rearrangement of furniture or other hanging items is often discouraged or rendered less attractive because of the disincentive to tamper with the location of the existing item. In addition to the time that is wasted and the less than aesthetically satisfactory arrangements that are often lived with, the removal and reaffixing nails or screws is a common occurrence that causes damage to the wall surface and sometimes failure of support for the hanging item. While prior artisans in the field have long recognized these difficulties and have created a myriad of devices aimed at solving them, the devices have fallen short of providing satisfactorily robust yet simple ways for the end user to hang an item.
More generally, prior to the present invention, there has been a need for an improved adjustable linear locking assembly that can be adjusted conveniently.
A few specific definitions and non-exhaustive comments are provided separately in this section, and apply to the defined terms themselves as well as their roots, derivatives and other variants evidently directed at the same concept. Due to the large number of embodiments and parts described in this specification, some words may be used overlappingly, etc. Nevertheless, upon a careful review of this specification, the applicable definitions of the various terms used herein should become clear in their context.
xe2x80x9cAutomaticxe2x80x9dadjustability means that the position of an item can be linearly adjusted: (1) without disengaging the item from a support or the rest of the assembly to a degree such that letting go of the item then would allow it to be released from the support or rest of the assembly (i.e., the adjustment can be done xe2x80x9cin situxe2x80x9d), (2) without requiring movement of the item to a position significantly distant from the position being sought, and (3) without requiring direct manipulation (by hand or by tool) of any portion of the assembly that is inconveniently concealed from reach by the item. Automatic activation of adjustment can be achieved by the user manually applying a selected force or series of forces on the item itself, and/or on a part of the assembly that is conveniently accessible (for example, an activation trigger). The term xe2x80x9cautomaticxe2x80x9d is not meant to exclude devices that incorporate the automatic nature of the invention taught herein, but simply add an additional locking means requiring some user interaction with a concealed part of the assembly (e.g., an added security locking means that requires a tool for initial unlocking) prior to an otherwise automatic process of adjustment.
xe2x80x9cContinuousxe2x80x9d adjustability means that adjustment occurs over a substantially continuous range rather than falling into a discrete group of selectable positions. This definition is not intended to exclude mechanisms having a minor degree of discontinuities imposed by supplemental holding means, such as relatively fine incremental teeth, which are added to improve an otherwise continuous mechanism""s holding of a vertical position (as exemplified by the embodiment of FIGS. 35-41).
xe2x80x9cReady engagement and disengagement of the item,xe2x80x9d xe2x80x9creadily engageable and disengageable from the support,xe2x80x9d and the like, means that an item may be readily hung on a support and removed therefrom as desired, through facile manipulations that do not involve any significant disassembly or any detachment of parts of the assembly affixed to the support or the subject item.
Finally, terms such as xe2x80x9citemxe2x80x9d and xe2x80x9cframexe2x80x9d; and xe2x80x9cwallxe2x80x9d and xe2x80x9csupportxe2x80x9d are used herein with some overlap. For example, depending on the logical context, the term xe2x80x9citemxe2x80x9d may refer only to an item such as a diploma or picture, or it may also be inclusive of the xe2x80x9cframexe2x80x9d in which such an item is framed, and/or inclusive of an attached or incorporated mounting device. Likewise, the term xe2x80x9cframexe2x80x9d may refer just to the object in which an item is framed, or it may include the framed item and/or mounting device. These terms are intended to illustrate the concepts of the present invention, and are not meant to limit the types of items that may be adjustably held in position thereby. For example, a shelf or chair-back might be considered a xe2x80x9changing itemxe2x80x9d for the purposes of the present invention, despite the fact that neither has a distinct xe2x80x9cframe.xe2x80x9d
The prior art includes a series of patents directed to devices that provide two-way adjustability that is vertically neither continuous nor automatic. These patents include U.S. Pat. No. 5,480,120, issued Jan. 2, 1996 to Bruner; U.S. Pat. No. 3,945,599, issued Mar. 23, 1976 to Spier et al.; U.S. Pat. No. 3,063,666, issued Nov. 13, 1962 to Morrison; U.S. Pat. No. 2,757,890, issued Aug. 7, 1956 to Sutton et al.; and U.S. Pat. No. 2,740,602, issued April 3, 1956 to Wofford. The devices taught in each of these patents essentially comprise a first portion having a series of horizontal slots (or pairs of slots) and a second portion comprising an opposing hook(s) or the like which seats in any member of the series of horizontal slots. Some of the aforementioned patents disclose devices with the first portion attached to the wall and the second to the picture, while the others teach the converse arrangement. In either case, a measure of vertical adjustability is provided by disengaging the hanging item and its associated hanging means from the wall support means, and reseating the hook in a different member of the series of horizontal slots. In most of the devices, horizontal adjustability is provided by the hook(s) or the like being free to slide laterally along the horizontal length of the opposing slot(s) with which it is engaged. Most significantly, however, in each of these patents, the vertical adjustability is not substantially continuous in nature, and instead falls into a group of discrete selectable positions. Also, in each of these patents, vertical adjustment requires disengagement of the hanging item from the wall support, meaning that if the person hanging the item were to let go of the item, it would presumably drop to the floor. Moreover, reengagement during vertically adjustment can involve somewhat of a xe2x80x9cblindxe2x80x9d process.
The prior art also teaches devices which provide for continuous, two-way, but non-automatic adjustability, requiring that adjustments be made directly to an assembly residing behind the hanging item in a fashion which is not conveniently accessible. For example, U.S. Pat. No. 4,892,284, issued Jan. 9, 1990 to Kelrick, and U.S. Pat. No. 2,791,388, issued May 7, 1957 to Hirt, both teach devices that allow for two-way adjustability effected by the manipulation by tool (e.g., screwdriver) of a rack and pinion or the like. These devices present a clear inconvenience in that the user is required to insert a tool between the hanging item and wall and then, with some precision, locate the adjustment means. In addition, these devices require that the user have a suitable tool handy whenever adjustment to the hanging item is desired, and they also tend to necessitate the existence of a substantial gap between the hanging item and the wall in order to accommodate the device as well as clearance for the tool to be inserted.
Another example of a two-way adjustable device is found in U.S. Pat. No. 4,549,713, issued Oct. 29, 1985 to Magadini. Magadini discloses vertically disposed rods which slide along a horizontal wall support, and upon which spring biased xe2x80x9cLxe2x80x9d or xe2x80x9cIxe2x80x9d shaped metal hanger straps are locked in place against downward vertical movement. This device, however, is not automatically adjustable. First, vertical adjustment requires direct manual location, manipulation (i.e., overcoming the spring bias of a hanger strap and moving it to a different position), and resetting of the hanger straps. Further, the Magadini device may require the hanging item to be removed from the wall in order to manipulate the hanger straps. Also, because the horizontal wall support is (by necessity) at the uppermost position compared to the rest of the assembly, part of the assembly itself is visible, which is generally not aesthetically desirable.
Another example of a non-automatic adjustable device is disclosed in U.S. Pat. No. 2,898,064, issued Aug. 4, 1959 to Scott. The Scott device comprises a beaded chain that attaches to the item to be hung, and an assembly that attaches to the wall and includes a horizontally sliding member with slots into which the beaded chain can be connected at various positions along the chain. This device is of course not automatic because the beaded chain must be manually reached, pulled out of the slots, and reinserted at a different position in order to accomplish vertical adjustment. It also appears that the hanging item may have to be disengaged from the wall for the beaded chain to be reinserted.
The prior art includes various other patents disclosing two-way, non-automatic adjustable devices. Beyond the disadvantages noted above, these devices require the hanging item be repeatedly removed, set somewhere, and then replaced, and further require some guesswork as to exactly where an item will hang after the device has been adjusted a given amount. This type of non-in situ adjustment process creates temporal lapses that undermine visual and mental comparison of the item hanging in different positions.
U.S. Pat. No. 4,641,807, issued Feb. 10, 1987 to Phillips teaches such a device. This device comprises a mounting stud attached to a slotted body plate that is secured to the wall by a screw passing through the slot and into the wall. When the screw is loosened, the body plate can be slid along and rotated about the screw; the body plate stays in position once the screw is retightened. This device requires that the hanging item be disengaged and set somewhere while the assembly is directly manipulated and a new configuration secured. It also appears that the device affords at most one screw to secure the body plate to the wall; thus, hanging an item anywhere other than with its center of mass directly above the screw will create a rotational torque in the plane of the wall tending to cause the whole assembly to rotate out of level, undermining horizontal adjustability.
The prior art also includes patents directed to devices that provide vertical but not horizontal adjustability. One example is U.S. Pat. No. 4,557,455, issued Dec. 10, 1985 to Benjamin, and disclosing a toothed latching device. Beyond not providing horizontal adjustability, however, this device is not fully automatic as it only allows upward movement when engaged, i.e., it is xe2x80x9cone-way.xe2x80x9d In order to adjust a hanging item downwardly, the item must first be moved all the way to the top of its adjustment range, whereat the latch disengages, and then all the way to the bottom of its adjustment range whereat the latch reengages. Then, with the latch engaged, the item is moved upwardly until the desired (originally) lower position is reached. Consequently, whenever a hanging item is desired to be moved downwardly at all, it must be moved entirely out of its existing position, the previous position (minus the desired downward adjustment) remembered or marked, and then relocated. Each time an item is adjusted just past its desired position, the entire process must be repeated.
Another type of prior art device providing vertically-only adjustability is disclosed in U.S. Pat. No. 3,285,549, issued Nov. 15, 1966 to Cook, and in U.S. Pat. No. 2,943,831, issued Jul. 5, 1960 to Goss. These devices are non-automatic and operationally somewhat similar to the Magadini device, in that they each require inconvenient manual manipulation (the hanging item must be tilted away or removed from the wall) of a recessed assembly in order to effect adjustment.
Finally, U.S. Pat. No. 1,432,206, issued Oct. 17, 1922 to Poole, Jr., discloses a marginally relevant device that provides automatic, vertically-only adjustability. The device is a mirror support comprising a clamping portion affixed to the mirror, and a vertically disposed rod affixed to the wall. When the mirror is disposed in the vertical plane, the clamping portion clamps the rod; when the bottom of the mirror is tilted upward, the clamping portion no longer clamps the rod, allowing it to slide up or down on the rod until the mirror is again disposed vertically by the user. In as much as there appears no ready way to remove the rod from the wall or to remove the clamp from the mirror, the clamping portion is permanently secured in sliding relation to the rod, and there is no way to readily engage or disengage the mirror from the wall. It should also be noted that, because the portion of the device which provides the range of vertical adjustability (namely, the rod) is attached to the wall, visible overhang of part of the assembly itself is apparently unavoidable. It should be further noted that the Poole, Jr. device necessitates a significant gap between the hanging item and the wall. This is because the clamp must be distanced from the rear of the item to provide clearance for pivoting the item on the rod without hitting the rod, and because the portion of the clamp facing the wall must have clearance from the wall in order to allow pivoting on the rod without hitting the wall.
The prior art also contains numerous teachings concerning horizontally-only adjustable devices, for example, U.S. Pat. No. 5,454,542, issued to Hart on Apr. 19, 1994.
Thus, there clearly remains a need for a mounting device that allows for readily disengageably hanging an item with automatic, substantially continuous vertical adjustability. A further need is for a mounting device that provides automatic, substantially continuous, two-way adjustability, with or without ready disengageability of the supported item. Another need is for a mounting device that can increase the usable horizontal hanging area for items that require the support of a wall stud, so that the position of studs is not as determinative of the placement of such items. There is also more generally a need for an improved adjustable linear locking assembly that allows automatic, substantially continuous adjustment to the linear position of a locking element. The foregoing description of prior art and needs is not meant to limit the invention in any way, and it should be understood that an embodiment of the invention need only serve one of the aforementioned needs or one of the other needs described or alluded to herein.
The present invention provides an adjustable linear locking assembly, such as may be used in a mounting device or other suitable applications, which assembly allows automatic, substantially continuous adjustment to the linear position of a locking element such as an interface. The above and other objects, features, and advantages of the present invention will become apparent from the following description of preferred embodiments and the accompanying drawings.